Scientific Seminars

Parent population of flat-spectrum radio-loud Narrow-Line Seyfert 1 Galaxies

Marco Berton
Universita' di Padova

2015-11-24    14:00    Brera - Cupola fiore

Flat-spectrum radio-loud narrow-line Seyfert 1 galaxies (NLS1s) are a class of gamma-ray emitting active galactic nuclei (AGN) recently discovered by the Fermi Satellite. These sources often exhibit some blazar-like properties usually explained with the presence of a relativistic jet viewed at small angles. When observed at larger angles, according to the unified model blazars appear as radio-galaxies, and we expect to observe an analogue parent population for beamed NLS1s. In this study we studied the nature of this population by examining the physical properties of three samples of parent candidates: steep-spectrum radio-loud NLS1s, radio-quiet NLS1s and disk-hosted radio-galaxies. We first studied the optical spectra of these sources to determine their black hole mass and Eddinton ratio. We then focused on the [OIII] lambda 4959,5007 lines to investigate the properties of their narrow line region and its interaction with the relativistic jet. Finally we analyzed their radio luminosity function, which allowed us to determine the relations linking the samples.